original_kernel/arch/ppc64/xmon/start.c

186 lines
3.0 KiB
C

/*
* Copyright (C) 1996 Paul Mackerras.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/config.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/sysrq.h>
#include <linux/init.h>
#include <asm/machdep.h>
#include <asm/io.h>
#include <asm/page.h>
#include <asm/prom.h>
#include <asm/processor.h>
#include <asm/udbg.h>
#include <asm/system.h>
#include "nonstdio.h"
#ifdef CONFIG_MAGIC_SYSRQ
static void sysrq_handle_xmon(int key, struct pt_regs *pt_regs,
struct tty_struct *tty)
{
/* ensure xmon is enabled */
xmon_init(1);
debugger(pt_regs);
}
static struct sysrq_key_op sysrq_xmon_op =
{
.handler = sysrq_handle_xmon,
.help_msg = "Xmon",
.action_msg = "Entering xmon",
};
static int __init setup_xmon_sysrq(void)
{
register_sysrq_key('x', &sysrq_xmon_op);
return 0;
}
__initcall(setup_xmon_sysrq);
#endif /* CONFIG_MAGIC_SYSRQ */
int
xmon_write(void *handle, void *ptr, int nb)
{
return udbg_write(ptr, nb);
}
int
xmon_read(void *handle, void *ptr, int nb)
{
return udbg_read(ptr, nb);
}
int
xmon_read_poll(void)
{
return udbg_getc_poll();
}
FILE *xmon_stdin;
FILE *xmon_stdout;
int
xmon_putc(int c, void *f)
{
char ch = c;
if (c == '\n')
xmon_putc('\r', f);
return xmon_write(f, &ch, 1) == 1? c: -1;
}
int
xmon_putchar(int c)
{
return xmon_putc(c, xmon_stdout);
}
int
xmon_fputs(char *str, void *f)
{
int n = strlen(str);
return xmon_write(f, str, n) == n? 0: -1;
}
int
xmon_readchar(void)
{
char ch;
for (;;) {
switch (xmon_read(xmon_stdin, &ch, 1)) {
case 1:
return ch;
case -1:
xmon_printf("read(stdin) returned -1\r\n", 0, 0);
return -1;
}
}
}
static char line[256];
static char *lineptr;
static int lineleft;
int
xmon_getchar(void)
{
int c;
if (lineleft == 0) {
lineptr = line;
for (;;) {
c = xmon_readchar();
if (c == -1 || c == 4)
break;
if (c == '\r' || c == '\n') {
*lineptr++ = '\n';
xmon_putchar('\n');
break;
}
switch (c) {
case 0177:
case '\b':
if (lineptr > line) {
xmon_putchar('\b');
xmon_putchar(' ');
xmon_putchar('\b');
--lineptr;
}
break;
case 'U' & 0x1F:
while (lineptr > line) {
xmon_putchar('\b');
xmon_putchar(' ');
xmon_putchar('\b');
--lineptr;
}
break;
default:
if (lineptr >= &line[sizeof(line) - 1])
xmon_putchar('\a');
else {
xmon_putchar(c);
*lineptr++ = c;
}
}
}
lineleft = lineptr - line;
lineptr = line;
}
if (lineleft == 0)
return -1;
--lineleft;
return *lineptr++;
}
char *
xmon_fgets(char *str, int nb, void *f)
{
char *p;
int c;
for (p = str; p < str + nb - 1; ) {
c = xmon_getchar();
if (c == -1) {
if (p == str)
return NULL;
break;
}
*p++ = c;
if (c == '\n')
break;
}
*p = 0;
return str;
}